#include <bits/stdc++.h>
 using namespace std;
 using pii = pair<int, int>;
 using ll = long long;
 #define rep(i, j, n) for(int i = j; i < (int)(n); i++)
 const ll MOD = 1000000007;
 const ll INFL = (1LL << 60);
 const int INFI = (1 << 30);

 int main() {
   int N, K; cin >> N >> K;
   vector<int> A(N);

   rep(i, 0, N) cin >> A.at(i);

   sort(A.begin(), A.end(), greater<int>());

   int ans = A.at(0);
   rep(i, 1, K) {
     if (A.at(i) > 0) ans += A.at(i);
     else break;
   }

   cout << ans << endl;
 }